Gas drainage sealing mechanism and optimization of key leakage parameters: analysis, experiment, and field verification

• Published in: Arabian journal of geosciences 2022-09, Vol.15 (17), Article 1431
• Main Authors: Hong, Zi-jie, Xiong, Zu-qiang, Wang, Cheng
• Format: Article
• Language: English
• Subjects: Boreholes; Coal; Coal mines; Drainage; Earth and Environmental Science; Earth science; Earth Sciences; Engineering; Leakage; Mining accidents & safety; Optimization; Original Paper; Parameters; Sealing
• ISSN: 1866-7511; 1866-7538
• DOI: 10.1007/s12517-022-10676-4

Low gas drainage efficiency is one of the important factors that cause coal mine accidents. Gas leakage leads to low extraction efficiency and sealing length; the diameter of the borehole, sealing strength, and other parameters determine the gas leakage. To improve the effect of gas drainage in a coal seam, the key optimization parameters and engineering practice results of gas drainage were studied. The solution equation of the leakage circle area and the gas leakage was established, the parameters that affect gas leakage were analyzed, and the gas drainage test technology and dual-liquid sealing material were studied. At the same time, a field validation test was completed. The results show that the sealing length and strength are the main factors that affect the sealing performance. The theoretical results show that the sealing length is 6 m and the sealing strength is 11 MPa; also, the gas extraction effect is the best. A new type of hole sealing method combining with the properties of the dual-liquid sealing material, that is, a “two plug and one injection” type, is proposed. Field practice verifies the rationality of optimized parameters and achieves good engineering results. It is concluded that the key sealing parameters that were determined and the dual-liquid sealing material that was developed have good promotion value.